科学家相信一些致癌物质、细胞内DNA 分子意外地重新排列和 过滤性病毒感染等，都会触发癌症的发生。

Scientists believe that certain carcinogens, accidental rearrangement of DNA molecules in a cell, and virus infection can all be factors that trigger the action of cancers.

youdao

吉福德说：“我们通过这些发现急需确定的问题，是过滤性病毒的分布情况，它们的传播途径，以及它们已经出现多长时间了。”

Gifford said: "we found an urgent need to identify these issues is the distribution of viruses, their transmission, as well as how long they already had."

youdao